Doubleisomerization / cycloisomerization / aromatization of 1-(allyloxy)-2-(cyclopropylmethyl)benzenes to give 2-ethyl-3-isopropylbenzofurans using multitasking single rhodium catalyst

2021 ◽  
Author(s):  
Yuta Sato ◽  
Tsuyoshi Matsuzaki ◽  
Tsunayoshi Takehara ◽  
Makoto Sako ◽  
Takeyuki Suzuki ◽  
...  
Keyword(s):  
Rhodium Catalyst ◽  
Reaction Vessel ◽  
Chemical Transformations ◽  
Catalyst Systems ◽  
Multiple Chemical ◽  
Single Reaction

Multitasking single-catalyst systems that allow multiple chemical transformations within a single reaction vessel are important for the development of eco-compatible chemistry. Here, we have developed a rhodium-catalyzed system that transforms...

scholarly journals Combined heterogeneous metal/organic catalysts for eco-friendly synthesis

2015 ◽  
Vol 87 (9-10) ◽  
pp. 1011-1019 ◽  
Author(s):  
Armando Córdova
Keyword(s):  
Reaction Vessel ◽  
Sustainable Chemistry ◽  
Selective Synthesis ◽  
One Pot ◽  
Complex Molecules ◽  
Metal Organic ◽  
Quaternary Stereocenters ◽  
Catalyst Systems ◽  
Multiple Relay ◽  
Single Reaction

AbstractThe interplay and synergistic cooperation between homogeneous and heterogeneous catalyst systems is of utmost importance in nature. It is also applied in chemical synthesis. Here, it can allow for new reactivity, which is not possible by the employment of a single catalyst, and promote the catalysis of multiple transformations in a one-pot sequence. This could overall lead to novel reactions and the development of sustainable chemistry. In this context, a versatile and broad synergistic strategy for the selective synthesis of valuable molecules with variable complexity and under eco-friendly conditions is disclosed. It is based on integrated heterogeneous metal/organo multiple relay catalysis, which is performed in a single reaction vessel, and allows for the assembly of complex molecules (e.g., heterocycles and carbocycles) with up to three quaternary stereocenters in a highly enantioselective fashion from simple alcohols and air/O2.

A palladium-catalyzed cascade process for spirooxindole: an alternative way for the synthesis of spiro(indoline-3,2′-quinazolin)-2-ones

2021 ◽  
Author(s):  
Abhilash Sharma ◽  
Dhiraj Dutta ◽  
Pranjal Gogoi
Keyword(s):  
Reaction Vessel ◽  
Cascade Process ◽  
One Pot ◽  
Arylboronic Acids ◽  
One Pot Synthesis ◽  
Synthetic Strategy ◽  
Palladium Catalyzed ◽  
Single Reaction

A palladium-catalyzed synthetic strategy has been developed for one-pot synthesis of functionalized spiro(indoline-3,2′-quinazolin)-2-one derivatives from 2-aminobenzonitriles, arylboronic acids and isatins. This cascade strategy proceeds via successive C–C and two C–N bond formations in a single reaction vessel.

Synthesis of 6-substituted indoloquinazolinones from arynes and 2-acyl-4-quinazolinones: a transition-metal free C–N and C–C bond formation strategy

2020 ◽  
Vol 44 (41) ◽  
pp. 17938-17953
Author(s):  
Abhilash Sharma ◽  
Pranjal Gogoi
Keyword(s):  
Transition Metal ◽  
Direct Synthesis ◽  
Bond Formation ◽  
Reaction Vessel ◽  
Metal Free ◽  
Synthetic Strategy ◽  
Single Reaction

A versatile transition-metal free synthetic strategy has been developed for the direct synthesis of 6-substituted indoloquinazolinones from 2-acyl-4-quinazolinones and aryne precursors. This cascade strategy proceeds via successive C–N and C–C bond formation in a single reaction vessel.

scholarly journals A domino reaction for generating β-aryl aldehydes from alkynes by substrate recognition catalysis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Weiwei Fang ◽  
Felix Bauer ◽  
Yaxi Dong ◽  
Bernhard Breit
Keyword(s):  
Substrate Recognition ◽  
Domino Reaction ◽  
Chemical Transformations ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Consecutive Reaction ◽  
Aryl Aldehydes ◽  
Rh Catalyst ◽  
Catalyst Systems ◽  
Step Control

Abstract The development of universal catalyst systems that enable efficient, selective, and straightforward chemical transformations is of immense scientific importance. Here we develop a domino process comprising three consecutive reaction steps based on the strategy of supramolecular substrate recognition. This approach provides valuable β-aryl aldehydes from readily accessible α-alkynoic acids and arenes under mild reaction conditions, employing a supramolecular Rh catalyst containing an acylguanidine-bearing phosphine ligand. Furthermore, the synthesis of a key intermediate of Avitriptan using this protocol is accomplished. The first step of the reaction sequence is proved to be the regioselective hydroformylation of α-alkynoic acids. Remarkably, molecular recognition of the ligand and the substrate via hydrogen bonding plays a key role in this step. Control experiments indicate that the reaction further proceeds via 1,4-addition of an arene nucleophile to the unsaturated aldehyde intermediate and subsequent decarboxylation.

scholarly journals Online HPLC Analysis of Buchwald-Hartwig Aminations from Within an Inert Environment

2020 ◽  
Author(s):  
Thomas C. Malig ◽  
Lars P. E. Yunker ◽  
Sebastian Steiner ◽  
Jason E. Hein
Keyword(s):  
Hplc Analysis ◽  
A Priori ◽  
Underlying Mechanism ◽  
Small Subset ◽  
Coupling Reactions ◽  
Chemical Transformations ◽  
Automated Sampling ◽  
Catalyst Systems ◽  
Temporal Profiles ◽  
Monitoring Platform

We have developed a reaction monitoring platform capable of automated sampling and online HPLC analysis to generate temporal profiles for reactions performed from within a glovebox. The device allows for facile reaction progress analysis to aid in mechanistic studies of air-sensitive chemical transformations. The platform has demonstrated high reproducibility regarding sample mixing, dilution, delivery, and analysis. We employed the sampling platform to acquire temporal profiles for a series of Buchwald-Hartwig aminations. Parallel coupling reactions using iodobenzene and bromobenzene both exhibit complex kinetics. A competition reaction including both aryl halides demonstrated high selectivity for iodobenzene indicative of catalyst monopoly. The temporal profile for the difunctionalized substrate 1,4-iodobromobenzene was unexpected based <i>a priori </i>and is indicative of a distinct underlying mechanism. We attribute this unanticipated reactivity to intramolecular catalysts transfer through the π system as seen in “living” polymerization transfer catalyst systems. This automated sampling platform has greatly increased mechanistic understanding by performing only a small subset of experiments.

Utility of the MÖssbauer Effect in the Assessment of Chemical Transformations in Unsupported Catalyst Systems as a Function of the Metal Salt

1980 ◽  
Vol 3 ◽  
Author(s):  
Mary L. Good ◽  
M. Akbarnejad ◽  
M. D. Patil ◽  
J. T. Donner
Keyword(s):  
Metal Salt ◽  
Chemical Characterization ◽  
Subsequent Treatment ◽  
Chemical Transformations ◽  
Unsupported Catalyst ◽  
Physical And Chemical Characterization ◽  
Initial Salt ◽  
Catalyst Systems ◽  
Physical And Chemical

ABSTRACTThis paper is presented to illustrate the utility of Fe-57 Mössbauer spectroscopy in the physical and chemical characterization of metallic catalysts as a function of preparation and subsequent treatment. The particular example chosen for investigation is the Ru-Fe bimetallic salt system which has significant potential as an active Fischer-Tropsch catalyst. The interpretation of the resulting Mössbauer parameters provides information on the chemical state of the metals as a function of treatment and initial salt properties and allows certain deductions to be made about particle size and solid state properties.

Integration of a Four-Step Reaction into One-Pot under the Coexistence­ of Silica-Gel-Supported Acid and Base Reagents: Synthesis of Benzo- and Naphthothiophenes Using NaHSO4/SiO2 and Na2CO3/SiO2

Synthesis ◽  
2019 ◽  
Vol 51 (12) ◽  
pp. 2572-2578 ◽  
Author(s):  
Mamiko Hayakawa ◽  
Tadashi Aoyama ◽  
Kyohei Nakaoka ◽  
Masayuki Kosuge ◽  
Akihiko Ouchi
Keyword(s):  
Silica Gel ◽  
Material Science ◽  
Reaction Vessel ◽  
One Pot ◽  
Biological Importance ◽  
Acid And Base ◽  
Conventional Methods ◽  
Unpleasant Smell ◽  
Single Reaction

A four-step synthesis of benzo- and naphthothiophenes that have biological importance and application in material science was integrated into a one-pot reaction by using silica gel-supported acid and base reagents, NaHSO4/SiO2 and Na2CO3/SiO2. The supported reagents provided acid and base environments on the surface of the supports without neutralization and worked separately in the same medium. The four-step reaction comprises (i) deacetylation of 3-halo-2,4-pentanediones to α-halo ketones, (ii) deacetylation of S-aryl thioacetates to arene­thiols, (iii) coupling of α-halo ketones and arenethiols to give α-sulfanyl ketones, and (iv) cyclization of sulfanyl ketones to benzo- and naphthothiophenes. The steps (i) and (iii) proceeded by Na2CO3/SiO2, and (ii) and (iv) by NaHSO4/SiO2. The four-step reaction proceeded efficiently by introduction of starting materials and reagents in a single reaction vessel. The starting materials were very easy to handle and unpleasant smell of aryl thiols that were used in conventional methods could be avoided. Novel thirty-nine benzo- and naphthothiophenes were synthesized by this method in excellent to fair yields.

scholarly journals Synthetic Utility of One-Pot Chemoenzymatic Reaction Sequences

Synlett ◽  
2019 ◽  
Vol 31 (03) ◽  
pp. 230-236 ◽  
Author(s):  
Tyler J. Doyon ◽  
Alison R. H. Narayan
Keyword(s):  
Reaction Vessel ◽  
Synthetic Methods ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Synthetic Utility ◽  
Molecular Complexity ◽  
Reaction Processes ◽  
Single Reaction ◽  
Sustained Increase

In recent years, there has been a rapid and sustained increase in the development and use of one-pot chemoenzymatic reaction processes for the efficient synthesis of high-value molecules. This strategy can provide a number of advantages over traditional synthetic methods, including high levels of selectivity in reactions, mild and sustainable reaction conditions, and the ability to rapidly build molecular complexity in a single reaction vessel. Here, we present several examples of chemoenzymatic one-pot reaction sequences that demonstrate the diversity of transformations that can be incorporated in these processes.

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